Three of the deaths were reported in Niigata prefecture while two others were killed in snow-related incidents in Fukuoka and Miyagi prefectures, the Kyodo News agency reported late Monday.
A 90-year-old farmer was found dead in Niigata after apparently falling into a snow-covered drain, while a 78-year-old man died after breaking his neck when he fell while removing snow from the roof of his house, the news agency said.
Niigata prefectural police also found a 62-year-old woman dead in a drain after she went out to shovel snow, Kyodo said.
A low-pressure system brought more snow and bitterly cold temperatures to the Hokuriku region along the Sea of Japan coast, according to the Japan Meteorological Agency.
The agency warned of heavy snow, avalanche risk and traffic disruption in the region and north-eastern Japan.
Up to 1,500 vehicles were stranded last week on a snowy road in a deadly winter storm in the Hokuriku region which led the government to dispatch more than 1,400 soldiers to the area. Some motorists were stuck on the road for three nights.
Japan has been pounded by storms this winter. The heaviest snow in four years hit Tokyo in late January, injuring hundreds of people and causing more than 700 traffic accidents.